Door-spring



(Model.)

L. M. DBVORE.

Door Springt No. 240,815.V Y Patented May 3,1881.

UNITED STATESv y PATENT OFFICE.,

LEVI M. Duvoan, on FREEDOM, ILLINOIS.

DOOR-SPRING.

SPECIFICATION forming" part of Letters Patent No. 240,815, dated May 3,1881.

Application filed February 24, 1881.

`-the followin gis a specification, reference being had to theaccompanying drawings.

The object of my invention is to provide a cheap, durable, and efiicientdoor-sprin g, which w1ll so act as to hold the door either open orclosed, as desired.

My invention relates to that class of doorsprings which consist of acoil of wire from which the ends of the wire forming it extend,constituting two arms,m one of which is attached to the doorjamb and theother to the door, through which arms is communicated the actuatingforce derived from the elasticity of the coiled wire constituting thespring. This style of spring is the simplest and cheapest in construction of any produced; but great difficulty In adapting it tothepurpose designed has been found in the fact that while it isnecessary for the proper operation of the spring that the axis of thecoil should remain parallel with the plane of the door, and that theplane of vibration of the arms should beat right angles with the planeofthe door, otherwise the force of the spring actuating the arms indifferent planes, the reaction from the same operating upon the oppositeends of the coil exerts a torsional strain, which causes the arms to'twist and throws the coil into such a position that its axis stands atan angle to the plane of the door and the spring becomes practicallyinoperative. In my invention this difficulty is overcome by bending thewire in such a manner that it forms a rigid axis for the spring,furnishing it with a bearing and maintaining it in a position at rightangles to the plane of vibration of the arms.

My invention is shown in detail in the accompanying drawings, in whichFigure l is a view of the spring attached to the door. Fig. 2 is avertical section of the spring. Fig. 3 is a top View of the door andspring, showing the door closed, and Fig. 4 is atop view of the door andspring, showing the door open.

Like letters indicate like parts in the different figures.

A represents the coil of wire, one end of (Model.)

which, diverging from the coil, forms the arm c. The other end passesdown through the center ofthe coil, and, emerging at the opposite end,is bent at right angles and forms the arm b, which is preferably longerthan the arm a.

Upon that portion ofthe wire passing through the center of the coil isthe core B. This core may be made of either wood or metal, and is of theproper size to fit easily but with approxi- 4mate closeness Within thecoil.

A sleeve, C, may be inserted between the core B and the coil. Ifpreferred, the sleeve may be made in sections, so as to permit the endsthereof to turn in opposite directions.

The arms are attached, the short one to the door and the long one to thejamb, bymeans of the clips or eyes c c, being so adjusted that as thedoor opens it spreads the arms and compresses the spring,the actuatingforce derived from the tension of which operates through the arms toresist the openingof the door until it is opened so far that the pointat which the power is applied has passed beyond the point around whichit operates, when the force of the spring acts to press the door open,as shown in Fig. 4. By reason ofthe wire passing through the center ofthe coil the arms diverge from the same end of the coil and from nearlya common point in its axis, so that their planes of vibration are nearlythe same, and their reactionary force being exerted at nearly the samepoint and almost directly against each other,.torsional strain is almostwholly removed. As the arms are vibrated the coil through the core B hasa bearing upon the wire b, passing through its center, which resistswhatever tendency there may be, through torsional strain or otherinfluence, to shift the axis of the coil, and thus maintains the coilrigidly in position.

An additional advantage of the construction of my spring is itseheapness, owing to the small amount of wire in its single pair of arms,and the ease and rapidity with which it is manufactured with suitablemachinery'.

What I claim as my invention,'and desire to secure by Letters Patent,is-

l. A door-spring formed of a single coiled wire the ends of whichdiverge from the same end of the coil, each arm coming from one and thesame coil, forming arms for attachment to IOO the door and jamb,substantially as and for to lshe door audjamb,substantia1ly as and forthe purposes set forth. the purposes set forth.

2. A door-spring formed of coiled Wire, one end of which passes throughthe center of the LEVI M' DEVQRE' coil, forming an axis upon which itmay bear, Witnesses: the ends of the Wire diverging from the same H. M.BARNUM, end of the coil, forming arms for attachment DANIEL C. STOVER.

